Field of the Disclosure
The present disclosure relates generally to processor systems and, more particularly, to power gating components of processor systems.
Description of the Related Art
Processing devices such as central processing units (CPUs), graphics processing units (GPUs), accelerated processing units (APUs), or individual processor cores can operate in different performance states. Such performance states include active states in which the processing device is performing tasks, idle states in which the processing device is not performing tasks, and power-gated states in which power is not being supplied to the processing device. Components in the processing devices can conserve power by idling when there are no instructions to be executed by the component of the processing device. If the component is idle for a relatively long time, power supplied to the processing device may be gated so that little or no current is supplied to the component, thereby reducing stand-by and leakage power consumption. For example, a processor core in a CPU can be power gated if the processor core has been idle for more than a predetermined time interval. However, power gating consumes system resources. For example, power gating requires flushing caches in the processor core, which consumes both time and power. Power gating also exacts a performance cost to return the processor core to an active state. The idle time interval that elapses before power gating a component of a processing device may therefore be set to a relatively long time.